Design and Development of an Atmospheric Water Harvesting System Using Solar-Powered Thermoelectric Cooling for Hot and Humid Water-Scarce Areas
Abstract
Atmospheric Water Harvesting (AWH) using Solar-Powered Thermoelectric Cooling (TEC) offers a decentralised, renewable means of extracting water vapour from humid air in hot, water-scarce regions. A major challenge in AWH is achieving efficient, low-maintenance cooling to condense moisture, a need that TEC modules address through their solid-state reliability. This study designs, develops and evaluates an AWH prototype that integrates a TEC module, a copper coil condenser, DC cooling fans, a water circulation pump and a solar-battery power supply to analyze temperature behavior, water collection and energy efficiency. Ambient water is circulated through the TEC to cool a copper coil below the dew point, inducing continuous condensation. The prototype was tested inside a sealed chamber over one-hour operating periods to compare copper coil orientation, coolant flow rate, and daytime versus night-time operation. Results show the horizontal copper orientation achieved a more uniform, lower steady-state surface temperature (20.5-21.0°C) than the vertical orientation (21.5-22.5°C), producing 55.4 mL of water compared to 33.0 mL, an increase of about 68%. Raising the coolant flow rate from 600 L/h to 1000 L/h increased water yield from 55 mL to 94 mL, while 800 L/h gave the lowest average copper surface temperature (21.1°C). Night-time operation consistently outperformed daytime operation, collecting an average of 83 mL compared to 76 mL, owing to lower ambient temperature and higher relative humidity. The system achieved a peak yield of 94 mL/h, comparing favorably with similar TEC-based AWH prototypes reported in the literature. Overall, the developed system demonstrates reliable, energy-efficient performance under hot and humid tropical conditions, supporting its potential as a practical, off-grid solution for atmospheric water harvesting in water-scarce areas.